@statechannels/channel-provider

🔌 Channel Provider

It exposes a global object called channelProvider that implements the EIP 1193 standard.

In the near future, it'll feature-detect if a wallet such as MetaMask has state channels support. If it does, the package does nothing; if it doesn't, it'll plug in the Embedded Wallet into a dApp.

Usage

Include the channel-provider.min.js file in your app via a script tag:

<script src="node_modules/@statechannels/channel-provider/dist/channel-provider.min.js"></script>

Then, enable the provider, passing on an URL to where the Wallet UI hosted.

This isn't final behavior. Eventually, the UI will be integrated inside a wallet like MetaMask, and the URL won't be necessary. Right now, we need this because of the usage of the .postMessage() API + CORS requirements.

window.channelProvider.mountWalletComponent('http://xstate-wallet.statechannels.org');

In order for the wallet connection to be useful, you'll want to enable it by calling .enable(). This method tells the wallet to establish a connection with the user's Web3 provider.

API

Method	Description
mountWalletComponent(url?: string)	Configures the dApp to be able to send/receive JSON-RPC messages.
enable()	Sends an EthereumEnable API call to the wallet.
send<ResultType>(method: string, params?: any[]): Promise	Sends a message to the wallet using JSON-RPC and returns the result, if any.
on(eventNameOrSubscriptionId: string, callback?: Function): void	Allows to register for events or subscriptions received from the wallet.
off(eventNameOrSubscriptionId: string, callback?: Function): void	Allows to un-register for events or subscriptions received from the wallet.
subscribe(subscriptionType: string, callback?: Function): Promise<string>	Allows to subscribe to an event feed, returns a subscriptionId that can be used later with .on() or .off().
unsubscribe(subscriptionId: string)	Removes all event listeners tied to a given subscriptionId and stops listening events on the requested feed.